Looper mechanism for sewing-machines.



PATENTED AUG. 13, 1907.

W. AMMERMAN. LOOPE'R MECHANISM FOR SEWING MACHINES.

APPLIUATIONIILED 0013.22, 1904.

2 SHEETS-SHEET 1.

t row i21 Mo MW PATENTED AUG. 1a, 1907. WgM. AMMERMAN. LOOPBRMEGHANISMFOR SEWING, MAGHINES. APPLIOATIOH FILED OUT 22 1904 Snow 1260a" QXWC000% UNITED STATES PATENT OFFICE.

WILLIAM M. AMMERMAN, OF NEW HAVEN, CONNECTICUT, ASSIGNOR TO THE EDWIN J.TOOF COMPANY, OF NEW HAVEN, CONNECTICUT, A CORPORATION OF NEW JERSEY.

LOOPER MECHANISM FOR SEWING-MACHINES.

Specification of Letters Patent.

Patented Aug. 13, 1907.

Application filed October 22, 1904. Serial No. 229,628.

To all whom it may concern:

Be it known that 1, WILLIAM M. AMMERMAN, a citizen of the United States,and a resident of New Haven, in the county of New Haven and State ofConnecticut, have invented certain new and useful Improvements in LooperMechanisms for Sewing-Machine s, of which the following is aspecification.

This invention relates to improvements in that class of sewing machineemploying a rotary looper in the form of a hook that is supported andcarried directly by its driver independent of a supporting race-way, andwhile the improvements forming the subject-matter of my presentapplication may be applicable generally to different types of sewingmachines, they have been applied in the present case to a lock-stitchlooper mechanism that is particularly adapted to be used interchangeablywith a chain-stitch looper for rendering a machine capable of makingeither a lock or chain stitch; a type of such machine and one to whichmy present improvements are specially applicable being disclosed inanother application of mine filed of even date herewith and bearingSerial No. 229,627.

In the machine forming the subject-matter of my said other application,a rotary driving shaft at the un der side of the bed-plate is providedat its forward end with a head or disk having an opening or socket inits front side for the detachable connection therewith of either achain-stitch looper or a lock-stitch looper, the said chain-stitchlooper having been made a part of the subject-matter of my said otherapplication and the lock-stitch looper having been reserved as thesubjectmatter of the present application. In the construction of thislock-stitch looper or hook for interchangeable use with a chain-stitchlooper, it has been one of the objects of my invention to provide thesame with means whereby it may be readily and conveniently connectedwith and disconnected from the driver by any ordinary or unskilledoperator.

Another object of the invention has been to so organize and associatethe looper and its normally contained bobbin-case and bobbin that suchparts will retain their operative relation when the looper isdisconnected from its driver and so provide for their more convenienthandling.

Another object of the invention has been to so associate the bobbin withthe bobbin-case that it will be retained in operative position thereinwithout the employment of the usual latch or other retaining device atthe front side of the bobbin.

Another object of the invention has been to so construct and associatethe parts that a bobbin may be employed which will carry a supply ofthread greatly in excess of that heretofore carried by bobbins in thesame or similar type of machine.

A further object of the invention has been to so construct and associatethe parts that the needle-thread loop may be carried around the bobbincontaining the under thread with a minimum degree of strain and frictionthereon.

These objects, and others to be hereinafter referred to, are secured bythe novel features of construction and combinations of parts embodyingmy invention as hereinafter set forth in detail and pointed out in theclaims.

Referring to the accompanying drawings forming part of thisspecification, Figure 1 is a partial front end elevation of a sewingmachine embodying my invention. Fig. 2 is a partial side elevation ofthe machine partly in section. Fig. 3 is a longitudinal section throughso much of the machine as is shown in Figs. 1 and 2. Fig. 4 is a frontend elevation of the looper driver with the looper removed. Fig. 5 is arear view of the looper driver partly in section. Fig. 6 is a rear endelevation of the looper and its contained bobbin-case with the bobbinremoved. Fig. 7 is a side view of the looper and its containedbobbin-case, and Fig. 8 is a side view of a chain-stitch looper that isinterchangeable with the lock-stitch looper or hook for connection withthe looper driver.

In the drawings, 1 indicates a portion of the bedplate of a sewingmachine having a hanger 40 at its under side in which is journaled arotary driving shaft 13 having attached to its front end a head or disk18 in the face side of which is formed an open socket 19 adapted toreceive the attaching shank of a loo per, the said shaft 13 with itsattached head or disk 18 constituting a looper driver. The looper shownin Figs. 1 to 7 inclusive of the drawings for connection with the saiddriver is what is commonly known as a hook and comprises a body portion2 havingaloop-seizing beak 3 and a central opening or chamber 4 for thereception of a bobbincase 5, which latter is retained in operativeconnection with the hook in the usual manner by means of a peripheralflange 6 thereon extending into a race-way groove 7 in the Wall of thesaid hook chamber 4 and is held in a non-rotary position with respect tothe hook by means of an arm 8 thereon loosely engaging a notched flange9 on the under side of the needle-plate 10.

In accordance with my present invention, the hook is provided at itsrear side with a tubular shank 20 as a means for effecting connectionwith the driver disk 18, the said shank being adapted to be insertedinto the open socket 19 of the said driver disk and be removablyretained therein by a suitable locking means, such means in the presentcase comprising a locking-lever 24 which is pivoted at 24 on the rearside of the driver disk and arranged with one end 25 normally extendingthrough a slot 18 in the driver disk to a positionfor locking engagementwith the hook shank 20 in aslot27 therein and its opposite or operatingend 28 extending to a convenient position to be reached by the operatoradjacent to the periphery of the disk. In placing the I may be adjustedrelatively to the bobbin-retaining hook inoperative connection with itsdriver, the beveled end 20 of the hook shank 20 in being entered intothe driver socket will engage with the inwardly projecting end 25 of thelocking-lever 24 and force the same laterally outward whereby it willride upon the outer surface of the shank until the slot 27 in the latterhas been brought into registry with it, at which time the lever willautomatically snap into the said slot under the action of a suitablespring, such as indicated at 30, and so operate to lock the hook inconnection With the driver. In order that the lever may operate to holdthe hook firmly in connection with the driver and against any unduemovement relative thereto, it is formed with a beveled or taperingsurface 25 at its point of engagement with the hook shank whichoperates, under the action of the spring 30, to exert a constantpressure against the said hook shank in a direction to hold some part ofthe hook, such as its rear wall 2, firmly against the adjacent wall ofthe driver, as most clearly shown in Fig. 3. As the inward pressure ofthe lever is yielding, under the action of its spring 30, it is therebyself-adjusting in its cooperation with the hook shank to prevent anyundue looseness between the hook and driver caused by Wear or otherwise.

To unlock the hook preparatory to its disconnection from the driver, itis only necessary for the operator to press inwardly upon the free endof the locking lever, which operation removes its inner or locking endfrom locking position in the slot 27 of the hook shank.

The described means for effecting locking connection between the hookand its driver are employed in the present case only for the purpose ofretaining connection between the hook and its driver in alongitudinaldirection or direction parallel with their axis, and a further means istherefore employed for the purpose of so connecting the said parts as tocause the hook to rotate with its driver; such means in the present casecomprising a locking projection 35 on the inner peripheral wall of thedriver socket entering a slot 36 in the hook shank 20.

In view of the detachable connection of the hook with its driver in themanner described, I have utilized such fact for the purpose ofdispensing with the usual bobbin-retaining latch at the front side ofthe bobbincase. This I accomplish by making both the hook and thebobbin-case open at their rear side in a position registering with theopening through the tubular attaching shank 20 of the hook as mostclearly shown in Figs. 3 and 6, whereby the bobbin, indicated at 1].,may be entered to or removed from its position in the bobbin-case at therear side of the hook.

With this construction of hook and bobbin-case, the latter willpreferably be provided with an inwardly turned bobbin-retaining flangeor wall 12 for engagement with the bobbin at the front side thereof andsuitable means will also be provided for engagement with the bobbin atits rear side so as to retain the same in operative position in thebobbin-case after the hook has been connected with its driver. The meansherein shown for so engaging with the bobbin at its rear side comprisesa retainer in the form of a screw 14 having a longitudinally adjustablescrew-threaded connection with the hook driver at the center of itssocket 19. An important feature of this retainer is the fact that itwall 12 at the front side of the bobbin-case so as to vary the spacebetween the same to accommodate bobbins of different lengths or sizesand also provide the proper clearance space between the said retainerand the adjacent end of the bobbin for the passage of the inner side ofthe needle-tln'ead loop when the latter is being carried around thebobbin by the hook in the usual manner. Another important feature of theretainer when supported relatively to the bobbin with a spacetherebetween for the passage of the 'thread loop as described, is thefact of its being rotatably movable with the supporting driver wherebyit will cooperate with the oppositely located rotatably movable bobbinto insure the more ready passage of the thread loop therebetween withoutundue strain or friction and so permit of the use of all grades andsizes of thread without liability of breakage to the same. A further andimportant feature of the hook and bobbin-case being open at their rearside and the bobbin being held in operative position at its rear end bythe said retainer 14 on'the driver, is the fact that the absence of therear walls of the said hook and bobbin-case provides an increased depthof chamber in the bobbin-case which enables me to employ an increasedlength of bobbin capable of carrying a supply of under thread greatly inexcess of that usually carried by the bobbin in the same or similar typeof machine.

The bobbin-case 5 at its front end projects forward of the front edge ofthe cast-off surface 2 of the hook and is formed with a rounded surfaceas shown to cause the front side of a thread loop to be readily castthereover when received from the said cast-off surface of the hook. Thisrounded so-called cast-over wall or surface of the bobbin-case, beingcircularly continuous at the peripheral edge of the bobbin-case anduninterrupted by latches or otherwise, insures the free and unobstructedpassage of the thread -loop thereover without undue strain or friction.The central opening at the front end of the bobbin-case Which is boundedby the inner edge of the flange 12 forms a so-called bobbin-ejectingopening through which the bobbin may be engaged for ejection through therear opening of the bobbin-case.

After a bobbin has been inserted to its normal operative position in thebobbin-case through the tubular shank 20 at the rear side of the hook,the end of the bobbin-thread will be passed through the open slot 36 inthe said shank 20 to the threading slot 37 in the bobbin-case whichleads from the rear edge of the latter to a position beneath theusualtension-spring 38, as indicated at Fig. 7. The said slot 36 in thehook shank 20 therefore serves both as a threading slot for thebobbin-thread and also as a means for effecting locking connection withthe driver in cooperation with the locking-projection 35 on the latter.

In Fig. 8 of the drawings, I have shown a chainstitch looper, designatedgenerally by and being of the same construction as that forming part ofmy said co-pending application, which is provided with an attachingshank 20 of the same construction as the shank 20 of the lock-stitchlooper or hook whereby the said,

two loopers may be interchangeable for detachable connection with thedriver.

1. In a sewing machine, the combination with a rotary looper driver, ofa rotary looper having a bobbin case and ably connected with said driverand having a part thereof bobbin supported therein, the said looper andbobbin-case both being open at their rear side for the insertion andremoval of a bobbin to and from a position within the bobbin-case, andan adjustable retainer supported in position for engagement with thebobbin at its rear side.

2. In a sewing machine, the combination with a rotary driver, of alooper having means for detachable connection with said driver and alsohaving a bobbin-case and bobbin supported therein, the said looper andbobbin-case both being open at their rear side for the insertion andrelnoval of a bobbin to and from a position within the bobbin-case, andan adjustable retainer carried by the driver for engagement with thebobbin at its rear side.

3. In a sewing machine, the combination with a rotary driver, of alooper having means for detachable connection with said driver and alsohaving a bobbin-case and bobbin supported therein, the said looper andbobbin-case both being open at their rear side for the insertion andremoval of a bobbin to and from a position within the bobbin-case, and aretainer for engagement with the bobbin at its rear side having alongitudinally adjustable screw-thread connection with the driver.

I. In a sewing machine, the combination with a rotary driver, of alooper detachably connected with said driver and having a bobbincase andbobbin carried therein, the said looper and bobbin-case both being openat their rear side for the insertion and removal of a bobbin to and froma position within the bobbincase, and the said hohbin-case beingprovided at its front side with an inwardlyprojecting bobbin-retainingflange and with an opening to permit of the entry therethrough of afinger or tool for engagement with the bobbin subsequent to thedetachment of the looper and its contained bobbin-case and bobbin fromthe rotary driver.

In a sewing machine, the combination with a rotary driver, of a looperdetachably connected with said driver and having a bobbin-case andbobbin contained therein, the said looper and bobbin-case both beingopen at their rear side for the insertion and removal of a bobbin to andfrom a position within the bobbin-case, and the said bobbin-case beingprovided at its front side with an inwardly-projecting bobbin-retainingflange and with an opening to permit of the entry therethrough of afinger or tool for engagement with the bobbin subsequent to thedetachment of the looper and its contained bobbin-case and bobbin fromthe rotary driver, and a thread-tension device attached to thebobbin-case on the peripheral wall thereof.

6. In a sewing machine, the combination of a rotary driver having alooper bearing surface, a looper detacharranged for engagement with saidbearing surface of the driver and also having a locking surface arrangedtransversely of its axis, and a spring-pressed locking device carried bythe driver and having a beveled surface yieldingly engaging the saidlocking surface of the looper and holding the latter in constantengagement with the driver.

7. In a sewing machine, the combination with a rotary driver having alooper bearing surface and also having a slot, a looper having means fordetachable connection with said driver and also having a part thereofarranged for engagement with said bearing surface of the driver, and aspring-pressed locking device carriedby the driver and having a beveledsurface for engaging with the looper within its said slot and holdingthe same in engagement with the driver, for the purpose set forth.

8. In a sewing machine, the combination with a rotary driver, of alooper having a tubular shank for detachable connection with said driverand also having a bobbin-case and bobbin supported therein, the saidlooper and bobbincase both being open at their rear side in a positioncoincident with the said tubular shank for the insertion and removal ofa bobbin to and from a position within the bobbin-case, and the saidtubular shank of the looper being provided with an open transverselyarranged slot for the passage therethrough of the bobbin-thread, and thesaid bobbincase being provided with an open thread ing slot incommunication with the said open slot of the looper shank.

9. In a sewing machine, the combination of a rotary driver having anopen socket at one end thereof provided with a locking projection on itsinner peripheral wall, a looper having a tubular shank for detachableconnection with the driver within its said socket and also having abobbin-case and bobbin supported therein, the said looper andbobbin-case both being open at their rear side in a position coincidentwith the said tubular shank for the insertion and removal of a bobbin toand from a position within the bobbin-case, and the said tubular shankof the looper being provided with a transversely arranged open slotadapted to receive the said locking projection in the driver socket whenthe shank is entered into the latter and also being adapted for thepassage therethrongh of the bobbin-thread.

Signed at New York, in the county of New York and State of New York,this 3rd day of October, A. D. 1904.

' WILLIAM M. AMMERMAN. Witnesses CHAS. F. DANE, E. M. FAITH.

